In recent years, in the bread manufacturing industry, a method for making broad with frozen dough is used as one of the means of rationalization of production. In this method, a process for making bread is interrupted by freezing dough and the frozen dough can be baked after the final proof following thawing, which enables the control of the process. As frozen dough endures a long-term storage, dispersion of the work in the bread-making process becomes possible. Further, if large-scale bakeries can send frozen dough from their factories to local bakeries, they can bake frozen dough in their ovens and offer just baked bread to the consumers at the stores. However, frozen dough has, at the same time, some defects; for example, the operation must be started earlier, because frozen dough takes much time to be completely thawed, and frozen dough must be baked soon after being thawed, because, after thawing, fermentation proceeds and dough cannot be preserved.
As another means of rationalization of production, a method for making bread with refrigerated dough is used. In this method, prepared dough is stored at a low temperature in such a range that dough may not freeze and is baked after the final proof as occasion demands. Compared with the method using frozen dough, this method saves cost in freezing, freeze-storage, freeze-transportation, thawing, etc., and also saves time up to the step of baking, for thawing is not necessary.
However, in cases where refrigerated dough is used, not only undesirable effects appear on dough, but also yeast in the dough will have a problem with respect to the storage stability and will deteriorate, because yeast ferments even during the storage of refrigerated dough. Consequently, the bread obtained by baking such dough has a small volume (specific volume) and is poor in appearance and crumb properties.
To solve these problems, the following are known as methods for making one-loaf bread, pizza, etc. using bread yeast having the refrigeration resistance: a method for making one-loaf bread and bins using bread yeast belonging to the genus Saccharomyces which is capable of controlling fermentation at a low temperature (-5 to 15.degree. C.), e.g., Saccharomyces cerevisiae IAM4274 (Japanese Published Unexamined Patent Application No. 195637/86); a method for making frozen bread dough using Saccharomyces cerevisiae IAM4274 (Japanese Published Examined Patent Application No. 58536/88); a method for making one-loaf bread, buns, etc., using bread yeast belonging to the genus Saccharomyces which shows the low-temperature-sensitivity and the freeze-resistance (Japanese Published Unexamined Patent Application No. 234939/92); a method for making pizza using bread yeast belonging to the genus Saccharomyces which is inactive but shows viability under refrigeration (Japanese Published Unexamined Patent Application No. 76348/93, EP487878A); a method for making one-loaf bread, etc. using bread yeast belonging to the genus Saccharomyces which shows the low-temperature-sensitivity and doesn't reduce the fermentability even when dough is refrigerated (Japanese Published Unexamined Patent Application No. 284896/93); and a method for making one-loaf bread, buns, etc. using yeast of which the fermentability is low-temperature-sensitive (Japanese Published Unexamined Patent Application No. 336872/93). Also is known bread yeast belonging to the genus Saccharomyces which shows the low-temperature-sensitivity at 0 to 10.degree. C. (EP556905A).
The present inventors obtained some of the yeast strains described in the above publications and measured the amount of carbon dioxide gas generated from dough containing the yeast strains after the storage under freezing and refrigeration to observe the fermentability of dough as shown in Table 1 below. However, the results were not satisfactory and the quality of the bread made from said dough was not good enough.
An object of the present invention is to make bread which is excellent in specific volume, etc., even with dough containing yeast which underwent storage under freezing and refrigeration.